Elastic strand for elastic fabrics and method of producing the same



Feb. 14, 1939. SICTLILLEY 2,146,966

ELASTIC STRAND FOR ELASTIC FABRICS AND METHOD OF PRODUGTNG THE SAME Filed Nov. 22,, 1957 15 ference with covering, weaving,

retained l i ch14, 1939 cums STATES ELASTIC STRAND FOR ELASTIC FABRICS "AND METHOD OF PRODUCING THE SAME Samuel 0. Lilly, Hamden, cm,

American Mills Company, New Haven,

assignor to. The

Conn, a

corporation of Connecticut r-Applic'ation November 2;,1937, Serial No. 175,925

14 Claims. (Ol. 117 -345) This invention relates elastic strands for elastic fabrics, and the methods of producing such strands,and is primarily concerned with providingfor elastic strands to textile covering material, and

vice versa. I

This application constitutes a continuation in part of my co-pending application filed October 20, 1936, Serial No. 106,581.

Methodsforanchoring textile covering material to-elastic strands have been proposed prior to the presentinvention,

as high cost, unsightliness of the product, interor other fabricating operations,'etc. i

As will be'apparent from the followin the present invention contemplates providing for the .securement of textile covering material to elastic strands by means of a thermo-plastic or heatactivatable adhesive-forming -material, rather than by a wet cement, as heretofore proposed.

One of the objects of the .present invention is to provide a superior method for securing elastic strands to textile covering material, wherein the securement or anchorage referred to is accomplished in a mannerfwhich will be effective but which will not occasion objectionable alterations in the appearance of the textile covering material overlying the said strand. A further object of the present invention is to provide a superior method for the manufacture of covered elasticstrands, in which textile covering material and the elastic strand-bodies are effectively anchored or secured to the covering material to guard against creeping or recession of the former with respect to the latter.

Another object of the present invention is to provide a superior method for producing covered elastic strands (comprising an elastic strandbody and a textile covering anchored thereto) which may be readily processed without materially interfering with the satisfactory operation of the covering, weaving or other fabricating apparatus. F I

A still further object of the present invention is to provide a superior covered elastic strand in which the elastic strand-body is effectively secured to atextile covering envelopabut in such manner as not to materially interfere with weaving or otherwise incorporating such covered elastic strands into elastic fabric.

Another object is to provide a superior elastic strand for incorporation into elastic fabric, which 15 provided with heat-activatable'means which.

will firmly adherethe s' d elastic strand to textile covering materialwhich may extend around I the strands or across the same, as for instance,

' in the case of the weft strands of an elastic fabric.

to improvements in the securement of but such proposals havebeen open toserious objections, such,.for instance,

- a Withthe above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes-all features inthe said dlSOlOSillB which are novel over the prior art.

In the accompanying drawing, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a broken view in side elevation showing -a thermo-plastic adhesive-forming ribbon and hovering-strands applied to an. elastic strandbody preparatory to softening or activating the said adhesive-forming ribbon by means of heat to adhere the covering-strands-tothe elastic strand-body;

Fig. 2 is an end view thereof; Fig. 3 is a broken, longitudinal, sectional view thereof taken on the line 3-3 of Fig. 1 but on a larger scale; Fig. 4 is a broken view substantially corresponding to 3 but showing the covered strand after the dry adhesive-forming ribbon has been activatedby heat to adhere thecovering-strands to the elastic strand-body;

Fig. 5 is a broken view in side elevation illustrating another mode of applying thermo-plastic adhesive-forming material and covering material to an elastic strand-body;

Fig. 6 is an end view thereof;

Fig. '7 is a broken, longitudinahsectional view taken on the line, 1-1 of Fig. 5 but on a larger scale;

Fig. 8 isa broken view in side elevation illustrating another mode of adhering covering materialto an elastic strand-body; and

Fig. 9 is a similar view of still another manner in which covering material and adhesive-forming material may be applied to an elastic strand-body. The particular covered elastic strand herein chosen for illustration in Figs. 1 to 4 inclusive, includesan elastic strand-body l0 which may be of round, rectangular or other cross-sectional form. The said elastic strand-body, whatever its cross-sectional shape, is of such dimension as will permit it to be readily woven, knitted or otherwise incorporated into elastic fabrics.

The elastic strand-body I0, above referred to, has helically wrapped around it one or more ribbon-likestrands l I of a suitable heat-activatable adhesive-forming material (specific examples of purpose of convenience of description may be aptly designated as'heat activatable or thermoplasticor heat-activatable thermo-plastic adhesive-forming material, inasmuch as the said material may be viewed as but a potential adhesive which is substantially dry and nonliquid at ordinary temperatures and which will not become cotton, regenerated cellulose, silk, wool, etc.

After both the thermo-plastic adhesive-forming material II and the covering material [2 are in place upon the elastic strand-body III, the partly-finished assembly may be subjected to heat, either before or after its introduction into a fabric, in any convenient manner which will render the adhesive-forming strands II or their equivalent sufficiently soft or fluid to adhere the covering-strands I! or their equivalent to the elastic strand-body as is schematically illustrated intFlg. 4, in which it will be noted that the adhesive. displaces outwardly to form stabilizingridge ll between the convolutions of the covering-strands l2.

Before the covering material such as the covering-strand l2 are applied over the thermoplastic adhesive-forming material such as the strands II, the said strands II or their equivalent thermo-plastic material are preferably treated to minimize the adhesiveness or tackiness of their outer surfaces at normal temperatures by any one of a variety of adhesivenessreducing treatments, such for instance as by passing the strand ll either before or after its application to the strand-body l0, through a bath of water-soluble gum combined with talc or by dusting with a mixture of equal parts of cornstarch and tale. A suitable gum for this purpose is- 10- oust-bean gum. Another mode of reducing the adhesiveness of the surfaces of the thermq-plastice strand II at normal temperature comprises passing the said strands ll through a dilute vapor of sulphur-chlorine and carbon tetrachloride so as to effect only a slight surface or skin cure of the said thermo-plastic material II.

The thermo-plastic material H is usually sufficiently soft to permit the covering material l2, when the latter is applied under tension, to yield and slightly displace, as shown in Fig. 3, though the said material ll does not substantially penetrate the material I! until heat is applied as described. The thermo-plastic adhesive-forming strands such as I I may be caused to substantially lose their identity as strands (Fig. 4) by employing a sumcient degree of heat over a relatively-long period of time though with some of the preferredthermo-plastic compounds the compound may be caused to sumciently penetrate the inner surface portions of the covering materialsuch as. I2 as shown in Fig. 4, by a relatively-brief heating at moderate temperatures (a temperature intermediate the boiling point of water and about 260 F).

The elastic strand-bodies Ill and the others herein referred to may be made of a wide variety of elastic materials such for instance as the vulcanized rubber compounds common in the textile art and preferably having a heat-disintegratingpoint at a temperature materially above the temperature at which the thermo-plastic adhesiveforming material used in conjunction with the said body-strand II will effectively soften or become active as an adhesive for the purpose intended.

In addition to the usual and other elastic compounds in the textile art, the following compound may be mentioned as particularly suitable for the production of elastic strand-bodies when cured for about forty-five minutes at approximately 260 F.: 1

% zinc salt of mercaptobenzothiazole- 1 10% di-ortho-tolylguanidine Zinc nxidn 5 Methylacrylic ester 20 The material from which the thermo-plastic adhesive-forming strand II and the other thermo-plastic materials hereinafter referred to may be constituted may vary widely but preferably such material should embody all of the following features:

(a) Water-insolubility to permit the laundering of the fabrics in which the elastic strands of the present invention may be incorporated;

(b) An initial effective softening-point or heat-activatabl point below the temperature at which the strand-body would be harmfully affected in order to avoid the weakening or disintegration of the said strand-body when the covered-strand is subjected to heat;

(0) An effective softening-point after it has once been activated, at temperatures above 212 F. in order to permit the laundering of fabrics in which the elastic strands of the present invention may be incorporated, in boiling water; and

(d) Characteristics which will not deleteriously afl'ect either the covering material or the elastic strand-bodies. 4

-The following examples of thermo-plastic adhesive-forming materials are given by way of illustration:

Example A Parts by weight Blended rubber (para and/or pale crepe). Zinc oxide 5 Zinc s p 5 Stearic acid 3 Sulphur 3% Mercaptobenzothiazole 1% Sym. di-beta-naphthyl-para phenylenediamine 1 Example B Rubber- 100 Dibutyl-ammonium-oleate- 3 Example 0 Rubber Meta-toluene-diamine 1 Example D Rubber 100 Di-penta-methylene-thiuram tetra sul Dhide 3 Example E Balata.

Example F Methyl-polyacrylate.

Example G Gutta-percha.

' Example H Rubber The rubber content in the above Examples A,

amaeoe B, c and 1), Should preferably be what is known in the trade as .pure rubber mix which is mechanically worked at high temperatures to produce a tough product with a minimum breakdown ofthe rubber itself.' The pure rubber hydrocarbon is then treated with compounds such, for instance, as those above given.

Formula A above given. is preferred over the otheri examples listed forthe reason that when subsequently heated for. approximately three minutes atabout 260'F,'.to adhere the strandbodiesto thechosen textile covering material, it then becomes vulcanized or set and is not again softenable except at. temperatures very materialto each other.

ly beyond those encounteredin any normal use to which elastic fabrics would be put.

The covering material herein referred to may be composed of a widevariety of textile or fibrous materials such, for instance, as cotton, wool, re-

generated cellulose, silk, etc., which specific examples are.substantially-inelastic as compared to the elastic strand-bodies hereinfreferred to.

;sive'. one} ormore composite strands, generally designated bythev reference character l3, may

,thermo-plastic adhesive-forming material and onei'or more filaments Iii of suitable textile covering material.

When .the covered elastic strand structure of Figs. 5 to '7 inclusive is subjected to heat, either before or after its introduction into a fabric, the thermo-plastic adhesive-forming filaments IE will become softened or activated and serve to adhere the filaments of covering material Hi to the elastic strand-body l4 and incidentally also When heated, as just described, the portionsof the filaments l5 or their equivalent, which are at the exterior of the strand l3, will penetrate inwardly rather than outwardly as is largely the case with the other adhesive-forming materials herein described.

* covering material such, for instance, as the V- coating l8 may be rendered sufficiently liquid or ering-strands l9, maybe applied as shown. Upon subjecting the assembly just referred to (Fig. 8)

to the action of heat, either before'or after its incorporation into a fabric, the heat-activatable' fluid to adhere the covering material l9 to the elastic strand-body I].

The coating l8, above referred to, may be applied to the strand -body l'| by passing the latter through a! liquid dispersion" of thermo-plastic material and then drying such dispersion before the coveringmaterialis applied and preferably after the surface of the 'now non-liquid thermoplastic material has been given an adhesivenessreducing treatment such. as has been hereinbefore referred to. i

A satisfactoryalleover coating maybe applied to elastic strand-bodies by dispersing Example A of thermo-plastic adhesive-forming material above given in from about 50 to 70% of naphtha or other dispersing medium. In this connection If desiredandas shown in Figs. to '7 inclu-- it is to be noted that the smaller cross-sectional area of the strand-bodies which are to be'coated, the less should be the thermo-plastic content in order to avoid undue thickness of the coating of thermo-plastic adhesive-forming material when the same is ultimately substantially dry.

If desired and as shown in Fig. 9, a suitable number of thermo-plastic adhesive-forming strands 20 may be extended longitudinally of an elastic strand-body 2| over which may be wrapped, braided or otherwise extended one or more strands 22 of textile covering material. The strands 20 before their application to the strandbody 2| should be suitably treated to minimize their adhesiveness at normal temperatures but in such manner as not to prevent their becoming adhesively active under the influence of heat.

When the elastic strand structure of Fig. 9 is subjected to the action of heat, either before or after being woven or the like, the substantiallylongitudinal thermo-plastic adhesive-forming strands 20 may be caused to lose their identity as strands andbecome sufficiently fluid or adhesive to adhere the covering material 22 to the elastic strand-body 2|.

If desired and as is common in the art, a second layer of textile material may be applied over the covering-material layers before described.

In each of the examples of the present invention above referred to, it will be noted that the textile covering material, whatever its character, is extended over the strand-body only while the therino-plastic adhesive-forming material is in a non-liquid or substantially-dry state, so that the ultimately-desired degree of adhesion between the strand-body and covering material is obtained only when the covering material, thermoplastic adhesive-forming material, and strandbody are concurrently subjected to heat.

It is also to be noted that preferably and as is the case with all of the foregoing examples of the present invention, the textile covering material is substantially unpenetrated by the thermo-plastic adhesive-forming material prior to the activating of the said thermo-rilastic adhesive-forming material by heat.

Strand-bodies with their applied thermo-plastic adhesive-forming material may be conveniently stored, shipped and sold in a naked or. uncovered state, and at the desired time introduced into covering machines to receive helical or.

braided covering'or the like, or introduced direct-v ly into fabric for adhesion to the-adjacent strands thereof, which strands in effect constitute covering material and when the fabric thus pro,-

duced is subjected to heat, the thermo-plastic adhesive-forming material upon the strand bodies will be activated and minimize any tendency of the said elastic strands to creep with respect tothe fabric in the event that such elastic strand-bodies should be ruptured or severed, as

forinstance by sewing or by excessive stretching.

The invention may be carried out in other specific ways than those herein set forth without: departing from the spirit and essential charac-,

invention, and the present emteristics of the I therefore, to be considered in all bodiments are,

respects as illustrative and not restrictive, and all changes coming. within the meaning and equivalency rangeof the appended claims are intended to be embraced therein. l

I claim:

1,.- A, method of jsecuring textile covering material to.

be woven or elastic strands of the type adapted to knitted into elastic fabric,'comprising: providing the exterior of an elastic strandbody with an elastic heat-activatable thermoplastic adhesive-forming material and positioning textile covering material over the said strandbody while the said adhesive-forming material is in a non-liquidstate; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesiveforming material of the said strand-body to cause the same to thermo-plastically adhere the said state with textile covering-strands: and then subjecting the assembly thus produced to the action of heat to activate the thermo-plastic adhesive-forming material of the said body-strand to cause the same to thermo-plastically adhere the said enveloping textile covering-strands to the said strand-body.

3. A method of securing textile covering material to elastic strands of the type adapted to be woven or knitted into elastic fabric, comprising:

providing the exterior of an elastic strand-body with an elastic heat-activatable thermo-plastic adhesive-forming material; then treating the thermo-plastic material of the said strand-body to minimize its adhesiveness at normal temperatures; then positioning textile covering material over the said elastic strand-body; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesive-forming material of the said strandbody to cause the same to thermo-plastically adhere the said textile covering material to the said strand-body.

4. A method of securing textile covering material to elastic strands of the type adapted to be woven or knitted into elastic fabric, comprising: providing the exterior of an elastic strandbody with an elastic heat-activatable thermoplasticadhesive-forming surface; treating the adhesive-forming material of the said strandbody to minimize its adhesiveness at normal temperatures; then enveloping the said strand-body with textile covering-strands; and then subjecting the assembly thus produced to the action of heat to activate the thermo-plastic adhesiveforming material of the said body-strand to cause the same to thermo-plastically adhere the said textile covering-strands to the said strandbody.

5. A method of securing textile covering material to elastic strands of the type adapted to be woven or knitted into elastic fabric, comprising: providing the exterior of an elastic strand-body with an elastic heat-aetivatable thermo-plastic adhesive-forming material; then treating the thermo-plastic material of the said strand-body tominimize its adhesiveness at normal temperatures; then, while the said adhesive-forming material is in a non-liquid state and after the same has been treated as just stated, positioning textile covering material over the said elastic strandbody; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesive-forming material of said strand-body to cause the same apropos and then subjecting the assembly thus produced to the action of heat to activate the thermo plastic adhesive-forming material of the said body-strand to cause the same to thermo-plastically adhere the said enveloping textile covering-strands to the said strand-body.

. '7. A method of securing textile covering material to elastic strands of the type adapted to be woven or knitted into elastic fabric, comprising: providing the surface of an elastic strand-body with an elastic heat-activatable thermo-plastic adhesive-forming material having an initial melting point at a temperature materially below the melting temperature of the main portion of the said body-strand and positioning textile covering material over the said strand-body while the said adhesive-forming material is in a non-liquid state; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesive-forming material of the said strand-body to cause the same to thermo-plastically adhere the said textile covering material to the said strand-body.

8. A method of securing textile covering material to elastic strands of the type adapted to be woven or knitted into elastic fabric, comprising: providing the exterior of an elastic strandbody with an elastic heat-activatable thermoplastic adhesive-forming material having a melting point materially lower than the melting point of the major portion of the said strand-body; then treating the thermo-plastic material of the said strand-body to minimize its adhesiveness at normal temperatures; than positioning textile covering material over the said elastic strandbody; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesive-forming material of the said strand-body to cause the same to thermo-plastically adhere the said textile covering material to the said strandrbody.

9. A method of securing textile-covering material to elastic strands of the type adapted to be woven or knitted into elastic fabrics, comprising: providing the exterior of an elastic strand-body with an elastic heat-activatable thermo-plastic adhesive-forming material and a textile covering material; and then subjecting the assembly thus produced to the action of heat to activate the said elastic thermo-plastic adhesive-forming material to cause the same to thermo-plastically adhere the. said textile covering material to the said strand-body, the said. textile covering material being substantially unpenetrated by the said thermo-plastic adhesive-forming material prior to subjecting the assembly to the action of heat 70 for the purpose described. h

10. As a new article of manufacture, an elastic strand of the type adapted to be adhered to textile covering material by heat and to be woven or knitted into elastic fabric, and comprising: an

11. As a new article of manufacture, an elasticstrand of the type adapted to be adhered to textile covering material by heat and to be woven or knitted into elastic fabric, and comprising: an elastic strand-body having its exterior provided.

with a non-liquid heat-activatable thermo-plastic adhesive-forming material serving to thermoplastically adhere the strand-body to textile cov-- ering material when heated in coniunction therewith; and an adhesiveness-reducing coating extending over the surface of the said thermo-plastic adhesive-forming material and serving to minimize the adhesiveness of the surface thereof at normal temperatures. 7

12. As a new article of manufacture, an elastic strand, of the type adapted to be adhered to textile covering material by heat and to be woven or knitted into elastic fabric, and comprising: an elastic strand-body having its exterior provided with a non-liquid heat-activatable thermo-plastic adhesive-forming material having a material-f ly-lower melting point than the major portion of the said strand-body and servingto thermoplasticaliy adhere the strand-body to textile covering material when heated in conjunction therewith.

13. As a new article of manufacture, an elastic strand of the type adapted to be adhered to textile covering material by heat and to be woven or knittedinto elastic "fabric, and comprising: an elastic strand-body having its exterior provided with a non-liquid heat-activatable thermo-plastic adhesive-forming material having a materially-lower melting point than the major portion of the said strand-body and serving to thermo-plastically adhere the strand-body to textile covering material when heated in conjunction therewith; and an adhesive-reducing coating extending over the surface of the said thermo-plastic adhesive-forming material and serving to minimize the adhesiveness of the surface thereof at normal temperatures.

- 14. A covered elastic strand of the type adapted to be woven or knitted into elastic fabric and comprising: an elastic strand-body; textile covering material surrounding the said strand-body and substantially unpenetrated by dissolved adhesive; and an elastic adhesive material thermoplastioally unitingthe said strand-body to the said textile covering material without substantially penetrating the latter and confined substantially entirely between the said strand-body and covering material.

SAMUEL C. LILLEY; 30 

